If we look closely at the logic in create_physical_mapping(), when
we're doing STRICT_KERNEL_RWX, we do the following steps:
- determine the gap from where we are to the end of the range
- choose an appropriate mapping_size based on the gap
- check if that mapping_size would overlap the __init_begin
boundary, and if not choose an appropriate mapping_size
We can simplify the logic by taking the __init_begin boundary into
account when we calculate the initial gap.
So add a next_boundary() function which tells us what the next
boundary is, either the __init_begin boundary or end. In future we can
add more boundaries.
Signed-off-by: Michael Ellerman <m...@ellerman.id.au>
---
arch/powerpc/mm/pgtable-radix.c | 32 ++++++++++----------------------
1 file changed, 10 insertions(+), 22 deletions(-)
diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
index 030543451229..0e87733eed80 100644
--- a/arch/powerpc/mm/pgtable-radix.c
+++ b/arch/powerpc/mm/pgtable-radix.c
@@ -255,17 +255,21 @@ static inline void __meminit print_mapping(unsigned long
start,
pr_info("Mapped 0x%016lx-0x%016lx with %s pages\n", start, end, buf);
}
+static unsigned long next_boundary(unsigned long addr, unsigned long end)
+{
+#ifdef CONFIG_STRICT_KERNEL_RWX
+ if (addr < __pa_symbol(__init_begin))
+ return __pa_symbol(__init_begin);
+#endif
+ return end;
+}
+
static int __meminit create_physical_mapping(unsigned long start,
unsigned long end,
int nid)
{
unsigned long vaddr, addr, mapping_size = 0;
pgprot_t prot;
-#ifdef CONFIG_STRICT_KERNEL_RWX
- int split_text_mapping = 1;
-#else
- int split_text_mapping = 0;
-#endif
int psize;
start = _ALIGN_UP(start, PAGE_SIZE);
@@ -273,7 +277,7 @@ static int __meminit create_physical_mapping(unsigned long
start,
unsigned long gap, previous_size;
int rc;
- gap = end - addr;
+ gap = next_boundary(addr, end) - addr;
previous_size = mapping_size;
if (IS_ALIGNED(addr, PUD_SIZE) && gap >= PUD_SIZE &&
@@ -289,22 +293,6 @@ static int __meminit create_physical_mapping(unsigned long
start,
psize = mmu_virtual_psize;
}
- if (split_text_mapping && (mapping_size == PUD_SIZE) &&
- (addr < __pa_symbol(__init_begin)) &&
- (addr + mapping_size) > __pa_symbol(__init_begin)) {
- if (mmu_psize_defs[MMU_PAGE_2M].shift)
- mapping_size = PMD_SIZE;
- else
- mapping_size = PAGE_SIZE;
- }
-
- if (split_text_mapping && (mapping_size == PMD_SIZE) &&
- (addr < __pa_symbol(__init_begin)) &&
- (addr + mapping_size) > __pa_symbol(__init_begin)) {
- mapping_size = PAGE_SIZE;
- psize = mmu_virtual_psize;
- }
-
if (mapping_size != previous_size) {
print_mapping(start, addr, previous_size);
start = addr;
--
2.17.2
